His might be using /scon -a or /scid -a to set /back on all networks...
Code:

on *:INPUT:#:{
  if ((/* !iswm $1-) && (%BackOnChanInput == on) && ($away)) {
    scon -a away
    scon -a nick %Normal.Nick
  }
}

DALnet: #HelpDesk and #m[color:#FF0000]IR[color:#EEEE00]C